Calder was always interested in the interaction between his hanging works and their surroundings. In this group of works made in the late 1930s, the relationship between foreground and background is not only emphasised, but becomes part of the work. In each one a painted wooden panel provides a backdrop in front of which coloured shapes are suspended, suggesting two-dimensional abstract paintings that have taken kinetic three-dimensional form. Many of these works have not been on public view for decades, and have never been exhibited together before.